the C2 testing option in CD Speed is limited to only a very few drives. most drives can't do this test.
Lite-On drives, and the Plextor Premium do this test. i'm not sure there are any other drives that do.
as for the Disc Info not working, do you have by any chance CloneCD or Alcohol 120% installed? these programs have a "Hide CDR info" option (or something similarly named) that prevents softwar from being able to read the CDR info (this has do to with bypassin certain copy protection schemes). if you have these programs (or maybe some other) make sure no such option is enabled.
Nvidia IDE drivers are know to be problematic w.r.t. optical drives.
i recommend you switch back to the MS drivers (built into WinXP) and see how things work for you.
One Ring to rule them all, One Ring to find them,
One Ring to bring them all and in the darkness bind them
In the land of Mordor, where the Shadows lie
M.C. Escher - Reptilien